Help with server/client using C

[gioravered]

Hi there.
I'm new to socket programming and have a question about it...
I wrote, with the help of a guide book, a code for a simple server, and another one for a client.

Q: Can i run the server app in Console and the client app in another Console? I mean, on the same machine? should they communicate? the client is trying to connect to my own IP..

If so, i'm having problems with connect() function.. but first I think i should find out if it's possible..

btw, I'm using C language..

Thank you very much,

giora.

[Rubberman]

Certainly. People do this (client and server on same system) all the time. The server uses listen() + accept(), the client uses connect(). Spend some $$ and get "Internetworking with TCP/IP, Volume III, Client-Server Programming and Applications" by Comer and Stevens (see Amazon.com). Prentice-Hall is (was) the publisher. Here is the Amazon.com link: Amazon.com: Internetworking with TCP/IP, Vol. III: Client-Server Programming and Applications, Linux/Posix Sockets Version (9780130320711): Douglas E. Comer, David L. Stevens: Books

Note that I paid $50 USD for it almost 20 years ago and it is only $67.50 USD today - a bargain at 2x the price! Trust me, it is one to keep on your book shelf. I have all three volumes, but that is probably overkill for you at this time.

[gioravered]

I guess that my problem is the connect() function that for some reason returns an error (-1) ...


thanks again.

[Rubberman]

Make sure all your setup works properly before you call connect(). Maybe one of those calls also returned an error and you didn't detect it?

[mstabie]

You can do a netstat -an to check if your server program has opened a socket in listen mode.
I tend to use
netstat -an | grep 7000
if I opened a server port on port number 7000. You should see a line line
tcp 0 0 0.0.0.0:7500 0.0.0.0:* LISTEN
if it worked. It could also be your trying to open a port that is already in use. As rubberman
suggested, check those return codes from listen and socket.